Range rules would be great.
This would be what I would recommend, it sounds complicated but it would be the only way to safely handle this event:
1. Rule: All firearms should be in gun cases. No holsters, exposed carry or slung rifles. When not firing, all firearms should be unloaded and in their case. When bringing firearms to the line, they should be in the case and the muzzle pointed downrange before opening the case. The case should be opened only at the firing line.
2. Rule: When out of the case, all firearms should have the bolts or actions open. A piece of weed wacker cord should be inserted into the chamber when they are out of the gun case and not being fired. When the case is opened, they should be grounded or on a table and pointing downrange when not being fired. The weed wacker cord (clear chamber indicator) allows the Range Officer to identify the line as being safe, before going forward to score or change targets.
3. Suggestion: There should be a fumble area (a place to show each other our firearms) set aside from the range and not pointing toward the camping area. There should be a table or tables there.
4. Suggestion: When pistol shooting 6' folding tables should be on the line and the shooters should rest their pistols on the table between shots. To not have the tables is dangerous. The pistol could be rested by dropping it down and pointing at the leg or foot. One table for 2 shooters. Shooters are not as likely to drop a rifle or shotgun down and point the muzzle at themselves.
5. Rule: Range Commands: (3 seconds between commands)
Shooters to the line
Your 3 minute preperation period begins now (RO observes the line and when everyone seems ready, ask the line if more prep period is needed, start the line if there is no response)
Load (only on command, the RO can observe the line and tell when the line has loaded)
Is the line ready (shooters should only respond if they are not ready)
Ready on the right
Ready on the left
All ready on the firing line
Commence fire and after the time limit decided on,
Most slowfire time limits are 1 minute per shot. Sighter periods may be from 5 to 10 minutes and the line is run the same way for sighters as record firing.
After the cease fire command:
Make the line safe, actions open, magazines removed, clear chamber indicators inserted (weed wacker cord)
Is the line safe (all shooters inspect the line and indicate the line is safe)
After the line is determined to be safe,
Go forward and score and change targets
If there is an emergency cease fire, all shooting stops and the line is made safe.. Indicate this by saying cease fire two or three times in a rapid and loud manner.
There should be 1 Chief Range Officer. In addition to the RO, one line officer for each 4 shooters.
6. Rule: If there is a malfunction on the range, the shooter is to raise their hand and keep the firearm downrange. The RO or a line officer goes to the shooter and helps clear the firearm. If a shooter turns and points an unloaded fiream at anyone they are warned the first time and ejected from the match on the second offense. If the fiream is loaded when sweeping anyone they are out of the shooting for the rest of the day.
7. Rule: When carrying a firearm at the range, the only safe way to carry is with the firearm vertical and the muzzle above the head of the person carrying it. This should only apply in carrying shotguns to and from the trap range firing line. Downward carry is not safe at a range except while shooting trap and the shooter is actually firing. If there is an accidental discharge with the muzzle down the shot or bullet can ricochet off the ground. Also, if downward carry is allowed, eventually someone will sweep someone with a firearm, usually at the offended person's legs.
8. Suggestion: Have a vertical gun rack at the trap range. Shooters should uncase their guns and put hem in the gun rack before shooting on the trap range. No more than 4 guns should be in the rack and only the guns of shooters that are due to fire. All other guns should be cased.
This is how matches are operated at our ranges. This is according to the NRA and military regulations. I have fired and observed these procedures at military ranges at Camp Perry, Ft. Smith and Ft. Benning.
I hope this helps. Operating a match, where the expertise of the participants is unknown can be difficult. We had the MS Senior Olympics today and one of the participants was loading a .22 rf revolver behind the line and pointing 180 degrees from the firing line. He was stopped immediately. The RO has to keep his/her eyes open.
Be sure there is a shooter's briefing outlining the rules you adopt. Furnish the rules you adopt on the forum. Don't assume everyone has read them.